Paper board machines



May 22, 1962 T. J. PESCATELLO PAPER BOARD MACHINES Filed Feb. 14, 1957 INVENTOR 5%;46 m

United States Patent 3,035,636 PAPER BOARD MACHINES Tufanio John Pescatello, New London, Conn., assignor to Robertson Paper Box Company Incorporated, Montvllle, Conn., a corporation of Connecticut Filed Feb. 14, 1957, Ser. No. 640,145 6 Claims. (Cl. 162-327) This invention relates to paperboard machines and more partciularly to the wet end of such machines utilizing a cylinder mold vat in which the fiber is deposited on 2 cylinder rotating in a vat suitably supplied with stoc The general object of the invention is to provide improvements in a cylinder mold and vat capable of producing an improved board without sacrificing production of board, and or producing a board of equal or improved quality at increased speed. It has been found possible to obtain an improved uniformity of surface for printing, improved quality for cutting and creasing, accomplishing a saving in white liner, increased production of regular board and specialties and a lower cost formula on specialties and regular board of an increased strength. In general, the deposition of the stock on the cylinder may take place in a much more uniform manner across the machine and in machine direction and there is also obtained a much improved distribution or orientation of fibers, making for a more compact smoother, stronger and better formed board without change in the stock with which the vat is supplied.

In previous board making machines, both counterflow and unifiow principles have been employed, and the stock has been introduced into the cylinder vat in a variety of manners. Essentially, however, in previously used equipment and methods of operating it, it is accepted theory that nearly all the formation takes place in the first 90 of cylinder rotation, where the fiber first contacts the cylinder and that during the remainder of the cylinder rotation in the vat, the formed stock is more or less dragged through the solution. The board produced therefore generally shows a definite tendency toward parallelism of orientation of the fibers and streakiness in the direction of movement of the cylinder, which type of orientation bears out the theory just mentioned, and also tends to produce an over all streaking, unevenness, and weakening of the board. The incoming flow of stock in a conventional vat further aggravates this unevenness of formation. In the machine and method of the present invention, the introduction of stock to the mold is accurately controlled with relation to the cylinder surface as it emerges from the body of stock within the vat and in such a manner as to produce a very desirable orientation of fibers and a much more uniform, dense and smooth formation, and with much less streaks.

A machine and method embodying the invention in a preferred form will now first be described with reference to the accompanying drawing and the features forming the invention will then be pointed out in the appended claims.

In the drawing:

FIG. 1 is a schematic cross section of a cylinder mold and vat embodying the invention in a preferred form;

FIG. 2 is an enlarged section showing an adjustable making board and also illustrating the flow conditions obtaining adjacent the board;

FIG. 3 is an enlarged schematic showing the fiber orientation in a board made in a conventional machine by conventional methods; and

FIG. 4 is a view similar to FIG. 3, showing a board made with the machine and method of the present invention, but from the same stock.

In the drawing, there is indicated at 10 a vat of conventional structure except as otherwise indicated, and having a generally semi-cylindrical form. The cylinder 11 rotates within this vat in the direction of the arrow 12, has a surface of fine wire mesh, over coarse wire, usually supported on small rods, is supported and rotated by means of a shaft 13 and is provided with a water discharge pipe 14 connected to the interior of the cylinder through an end plate structure 15 against which the end of the cylinder abuts and to which a reasonable seal is made by conventional means,

The vat 10 is generally concentric with the cylinder but the space between it and the cylinder may be varied as desired, on different machines. The vat is kept filled with stock 17 to some such level as indicated. In the vat shown, the stock is supplied to the vat adjacent the point where the cylinder emerges from the stock 17 within the vat circle, so that the operation is of the counterflow type. In its broader aspect, the invention is applicable to uniflow vats also. The stock is supplied from a body 19 within a vat 20 which in this example contains one or more baffles 21 over and under which the stock flows, however, other suitable baffling systems may be used also. The stock emerges from the vat by overflowing the edge of a making board 22, the design and arrangement of which constitutes an important feature of the present invention.

As shown in FIG. 2, the making board 22 is generally horizontal or may be varied and is supported by a pair of vertical adjusting screws 23, which, in turn, are supported in an upper frame member 24 within rotatable nuts 25, by turning which the board 22 may be located in a desired vertical position. Below board 22 and fastened thereto by heads 26 of the screws 23 is a U-shaped plate structure 27 which fits over a wall 28 of the vat and may he slid up and down thereon to vary the efiective height of this wall as the height of the board 22 is adjusted. Screws 23 pass through slots 29 in the board 22 and carry lock nuts 30 for securing the board in desired horizontal position with reference to the U-frame 27 and the screws 23. By loosening the lock nuts 30, the board may be adjusted horizontally toward and away from the cylinder mold 11 and then again fixed in position by retightening the lock nuts 39. A horizontal adjustment of several inches with a mold board approximately three to eight inches wide may thus be provided without difficulty, and a horizontal adjustment of several inches has been found advisable for various purposes. The back end of member 22 is preferably rounded as indicated at 31 and the front or discharge end is preferably beveled at 45 or thereabouts, as indicated at 32, and has sharp or slightly rounded edge 33. The inner plate of the U-shaped member 27 carries an adjustable wing baffle plate 34 mounted on the U-shaped member 27 by means of a hinge 35 and having means to hold the wing in adjusted position.

In a typical operation, the member 22 is set to a position about as indicated in the drawing, and in which the edge 33 may be in a plane through the cylinder axis at about 30 to the horizontal more or less and may be spaced from the cylinder by about one to four inches, more or less as shown. The flow of stock over the edge 33 follows substantially a course indicated in the central part of the stream, contacting the fibers already on the cylinder mold in point A and, by reason of velocity of the stock at this point, against the wire and downward to some extent, with part of it flowing in a retrograde direction to point B, at which point downward velocity of the stock entering the vat and flowing against the cylinder is relatively killed. The efiect of disturbance of the original orientation of fibers may continue to a' may be produced.

diminishing extent and to a lower point, such as the point C. By reason of the impingement of the stock against the cylinder, at a point where the web has been largely laid down, the amount of water flow through the cylinder mold from this impinging stock is greater than in conventional molds, and also the efiect is to agitate and dilute and redistribute the surface fibers already laid on the cylinder, mixing the outer portion thereof with the impinging fresh stock and temporarily producing in the outer part of the board, a more dilute and disturbed mass, from which water is then lost partly through the Wet sheet radially inward and partly to the outer liquid area of the mass. As will be apparent, a condition in which a substantial part of the board is finally laid down in the last half of the rotation of the cylinder 11 in the vat 19 is created rather than the first half or 90 and also the disturbance and agitation produce a much more uniform surface structure and also a structure in which the fibers are orientated in a much more heterogeneous fashion, and with less streaks in the finished results. This greater deposition of fiber on the mold in the last half of the mold rotation in the solution or diluted stock, tends to starve the first half of rotation of stock and which is very evident when this invention is used.

In FIGS. 3 and 4, there are shown schematically and to an enlargement of about ten diameters, typical areas of board made with conventional method and process (FIG. 3) and board made with the present method and machine. These figures have been prepared from samples in which a small quantity of colored fibers are incorporated in the stock, making it easy to observe the orientation. It will be noted that in the conventional board, the fibers are orientated predominantly in the direction X-X and in most cases relatively straight and subject to streaking while in the board of FIG. 4, the straight orientation has been disturbed and a major part of the fibers have also been crossed and curled or bent, as in the case of the fiber indicated at F.

In a board machine of this general type, an inherent balance of conditions exists, as determined by the speed of rotation of the cylinder, porosity of the wire surface, the rate of supply and extent of dilution of stock, the vat dimensions, and the water level within the cylinder, all of which conditions must be so related that a given rate of deposition of fibers on the cylinder is obtained in order that board of the required thickness and characteristics In a conventional vat there is thus little or no opportunity to control in any effective manner the rate of laying down of fibers as a function of angular position .of any given area of the cylinder or the orientation of fibers. With given speed of rotation of the cylinder and concentration of stock, the rate of supply must equal the rate of deposition or laying down. With the making board arrangement of the present invention, it is possible to control the rate of supply of stock as previously, and in addition by adjustment (principally the horizontal adjustment) of the board 22 to regulate the velocity and points at which the entering stock impinges upon the cylinder, or by combining the vertical and horizontal adjustment of the board to regulate this velocity (without changing the rate of supply of stock in terms of gallons per minute), while maintaining a fixed line of impingement of stock against cylinder, or adjusting the position of this line of impingement for best efiect.

The striking of the fresh stock against the already laid down fiber mass at a point where moisture therefrom has been largely drained into the cylinder, also causes absorption of water from the fresh stock of fibers into the already laid down partially formed web and discharge of this water into the cylinder, producing a radial compacting effect along with an interlacing of fibers or an orientation thereof at an angle to the plane of the sheet, producing again a very much improved surface structure.

When this invention is used it is then possible to lower the level of white water inside the cylinder mold and obtain a greater hydraulic head without streaks, skipping, etc., than in conventional cylinder mold arrangements, and this greater head permits use of more water into the vat which also improves formation and output.

This invention also permits the operator to control the level of the solution adjacent to the making board or pond for more uniform operation. It also permits operator to speed up the velocity of water over the outer edge 33 of the making board to control the action in the pond and to increase the total water used for changes in speed of the machine.

The battle 34 attached to the making board structure and moveable therewith, permits a control of the flow of stock upwardly to the making board 22, along a path generally indicated by arrow at X. The angle of the baflle 34 may be adjusted for the best flow over the making board 22, and the flow conditions above the outer end of this bafiie and from thereon up to the edge *of the board 22 will remain substantially unaltered as the height of the board is adjusted, since this adjustment does not disturb the relationship between board 22 and baffle 34. The horizontal adjustment of board 22 leaves the baffle 34 in unaltered position relative to the vertical adjacent baffie 21. Where, however, the horizontal adjustment makes a change in the typical flow path X desirable, this is readily accomplished by moving the bafile 34 about its hinge 35.

What is claimed is:

1. A paper board machine comprising a cylinder mold, means for rotating the mold, a stock vat having a vat circle in which the mold rotates, a fiow system for supplying stock to the vat, a making board positioned at the upper edge of the vat circle adjacent the mold where it emerges fi-om the vat circle, and means mounting the said board on the edge of the vat circle and for adjusting the position thereof horizontally, the How system comprising means for supplying the stock to the vat circle over the said making board and removing water from the interior of the mold, whereby the direction of stock flow within the vat circle opposite to the direction of rotation of the cylinder mold is maintained.

2. A paper board machine comprising a cylinder mold, means for rotating the mold, a stock vat having a vat circle in which the mold rotates, .a flow system for supplying stock to the vat, a making board positioned at the upper edge of the vat circle adjacent the mold where it emerges from the vat circle, and means mounting the said board on the edge of the vat circle and for adjusting the position thereof horizontally and vertically, the flow system comprising means for supplying the stock to the vat circle over the said making board and removing Water from the interior of the mold, whereby the direction of stock flow within the vat circle opposite to the direction of rotation of the cylinder mold is maintained.

3. A paper board machine comprising a cylinder mold, means for rotating the mold, a stock vat having a vat circle in which the mold rotates, a flow system for supplying stock to the vat, at making board, a vertically slidable member positioned at the upper edge of the vat circle adjacent the mold where it emerges from the vat circle for regulating the height of the said upper edge, and means mounting the said board on the said vertically slidable member for adjusting the position of the board horizontally, the flow system comprising means for supplying the stock to the vat circle over the said making board and removing water from the interior of the mold, whereby the direction of stock flow within the vat circle opposite to the direction of rotation of the cylinder mold is maintained.

4. A paper board machine comprising a cylinder mold, means for rotating the mold, a stock vat having a vat circle in which the mold rotates, a flow system for supplying stock to the vat, a making board, a vertically slidable plate positioned at the upper edge of the vat circle adjacent the mold where it emerges from the vat circle for regulating the height of the said upper edge, a making board at the top of the said vertically slidable member, a

baffie plate attached to the said slidable plate inside the vat and below the making board, and a vertical hafiie in the vat determining a path for upward flow of stock past the said bafiie plate and over the making board, the flow system comprising means for supplying the stock to the stock vat ahead of the said baffle for flow past the same and over the making board into the vat circle and means for removing water from the interior of the mold for maintaining a flow of stock in a direction opposite to that of the mold rotation.

5. A paper hoard machine comprising a cylinder mold, means for rotating the mold, a stock vat having a vat circle in which the mold rotates, a flow system for supplying stock to the vat, a making board, a vertically slidable plate positioned at the upper edge of the vat circle adjacent the mold where it emerges from the vat circle for regulating the height of the said upper edge, a making board at the top of the said vertically slidable member, a bafde plate, means adjustably attaching the baflie plate to the said slidable plate inside the vat and below the making board, and a vertical baffle in the vat determining a path for upward flow of stock past the said bafiile plate and over the making board, the flow system comprising means for supplying the stock to the stock vat ahead of the said bailie for flow past the same and over the making board into the vat circle and means for removing Water from the interior of the mold for maintaining a flow of stock in a direction opposite to that of the mold rotation.

6. A paper board machine comprising a cylinder mold, means for rotating the mold, a stock vat having a vat circle in which the mold rotates, a flow system for supplying stock to the vat, a making board, a vertically slidable plate positioned at the upper edge of the vat circle adjacent the mold where it emerges from the vat circle for regulating the height of the said upper edge, a making board at the top of the said vertically sliadble member, a bafiie plate hingedly attached to the said slidable plate inside the vat and below the making board, and a vertical bafiie in the vat determining a path for upward flow of stock past the said bafiie plate and over the making board, the flow system comprising means for supplying the stock to the stock Vat ahead of the said bafiie for flow past the same and over the making board into the vat circle and means for removing water from the interior of the mold for maintaining a flow of stock in a direction opposite to that of the mold rotation.

References Cited in the file of this patent UNITED STATES PATENTS OTHER REFERENCES Cook: Cylinder Machines from Paper Trade Journal, Feb. 8, 1952, pp. 21, 22, 24 and 26.

Goldsmith: Cylinder Machine Formation, TAPPI, Series XXI, pp. 125-134, June 1938.

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